Some video display apparatuses such as head-mounted displays are used by being worn on the head by users. A video display apparatus of this kind allows a user to view an image by forming the image in front of the user's eyes.
Some among the above video display apparatuses detect the user's head motion and display an image that is updated with change in position or orientation of the user's head. Such a video display apparatus allows viewing of videos that leave a user a “you are there” feeling, thereby finding application in virtual reality technology and so on. As an example, there is known a program that, while changing the orientation of a virtual camera placed in a virtual space to match with the user's head motion, displays a video indicating how the virtual space looks as seen from the virtual camera on a video display apparatus. This allows the user to view a video that leaves the user a sensation as if he or she were in a virtual space.